C++ compilations times

Curious about getting documentation or tips if possible.
I have build JDK14 yesterday from pkgsrc/wip and it took more than 6
hours on a box where the same JDK is built in about 3 hours for NetBSD or
OpenBSD...
Similar thing do happen with the other c++ beasts like KDE, it takes
roughly more x2 time to build.Insane.
I know zero about c++, but if someone can point to some docs about that
issue I will appreciate much.Thanks!
antonio.
--
"Men alt dette er ikke begyndelsen." - Knut HAMSUN, Mysterier, 1892